Bigbirds are not introduced until the second novel in the Charon Trilogy, "Charon's Children."

A species of intelligent dinosaur from the as-yet-unpublished1 second and third books of the Charon's Ark trilogy: Charon's Children and Charon is Coming.

The creation of science fiction writer Rick Gauger2. The nickname "big bird" is due to their muppetish appearance: big birds have a large forehead (a necessary adaptation of the cranium to house the neocortex); walk bipedally, and have forward-facing eyes with stereoscopic vision. They also have feathered heads, arms, and necks, which is not as far-fetched as it seems. Many fossils of small carnivorous dinosaurs have been found with the traces of feather impressions in the rock around them.

These traits make Charlie see in them a superficial resemblance to the beloved Sesame Street character. They inhabit a tribal civilization organized in Roosts (notably Sesame Roost, Capon Roost and Big Dustbath Roost) with approximately Bronze Age-level technology for the majority of the population, and access to high-tech and the Ark Computer granted to Capons, who can be likened to patricians or priests.

The Big Birds provide a great deal of comic relief to both novels, one or two even becoming featured characters, most notably Lower Capon 223, aka No Gonads, who is the first bigbird to communicate with Charlie Freeman. Charlie can speak to and understand the bigbirds via a babelfish-like technology supported by the Ark Computer. Charlie speaks in English, and computer implants pick up the meaning and broadcast it in Bigbird from a small speaker mounted on Charlie's chest. The computer also hears bigbird speech, and feeds an English translation into a set of earplugs for Charlie. Bigbird speech is described as sounding something like a gang of kindergarteners with woodwinds, punctuated by the occasional airhorn or goose.

The bigbirds are the children of a breeding program of forced evolution, instrumented by a select few members of the Charonese, otherwise known as the Crew. The Crew bred the bigbirds into intelligent, bipedal beings for the express purpose of Recruiting them into the Ark Computer once they achieved high enough intelligence. The bigbirds would then become Crewmembers. The Crewmembers keep the bigbirds from overunning the planet by enclosing them in a large area known as the Barrier. This plan is interrupted at the end of Charon's Ark by a largescale attack by the Proctor against the Crew.

The following is an excerpt from Gauger's holograph book, a collection of notes on Charon is Coming. The following was simply titled, "Dialog Two by the Grunts" and is an argument between two Bigbird soldiers (as heard via computer translation).

"In the name of Plentypossums, sergeant, let us ditch these greasy aliens immediately, and remove our copulations to another locality!"
"You ignorant yolk-sac! Do you not realize that there is nowhere to flee from the Proctor, except to the Capon Roost?"
"Then let us go there at once! I am fed up with being ordered about by bush-dwelling tribesroosters, capons, and overgrown eupantotheres from outer space!"
"Corporal, your thoughts are as the droppings of the far-flying quetzalcoatlus, i.e. they stink, and they fall wide of the mark! Go alone? Did you not see what the robot did to Lieutenant Fuzz? Best we go in convoy, with the humans! Thus staying under the guns of the human war machines! And the best way to do that, corporal, is to cling to the greasy aliens as though they were precious bags of the purest Rip Ruff Roost Ale!"

1 The third book is now completed, and the author is awaiting word from Del Rey on the possibility of publication. The first book, Charon's Ark, is available in used condition from various places.
2Also known for "The Vacuum-Packed Picnic" In: OMNI. September, 1979, Vol., 1, No. 12